Camera system

ABSTRACT

Camera system having a camera for a vehicle (F) for capturing the environment around the vehicle and a protection element. The camera has an optical element, with a light incidence portion (EB) and a retainer, which supports the optical element. The protection element is provided separately to the optical element and the retainer and is positioned at least on the light incidence portion (EB) of the optical element. The protection element has a sight opening, which exposes a use portion (NB) of the light incidence portion (EB). At least one gap between the optical element and the protection element for receiving a water drop (T), which is located on the use portion (NB), and a water drainage opening s distal from the sight opening is provided.

BACKGROUND OF THE INVENTION 1. Field of the Invention

The present invention relates to a camera system, in particular a camerasystem for a vehicle which has a protection element.

2. Description of the Related Art

For motor vehicles, it is legally prescribed to make so-called fields ofview around the vehicle visible for the driver during driving operation.Which fields of view have to be visible, is based on the type of themotor vehicle, for example, motor cycles, motor vehicles fortransporting passengers, motor vehicles for transporting goods, etc. Thevisibility of the fields of view has to be provided by a device forindirect view, and the fields of view have to be visible for the driversitting on the driver's seat all the time by using the device forindirect view. Dependent on the type of the vehicle and, in particular,on which areas around the vehicle can be directly viewed by the driver,different legal prescriptions require that certain fields of view arepermanently and reliably visible at all times by using the device forindirect view. In Europe, the fields of view which have to be reliablyvisible at any times for a driver are defined in the UN/ECE regulationsNo. 46. Further relevant norms and regulations include, for instance,ISO 5721, ISO 5006, ISO 16505, ISO 14401 and EU 167/2013. Beside thelegally required fields of view, often further areas around the vehicle,so-called regions of view, are made visible by devices for indirectview. Regions of view may contain legally prescribed fields of view.

Usually, the observation of the fields of view is possible with one ormore mirrors. However, mirrors have some drawbacks. For example, mirrorsshow a driver merely objects which are on the same side of the mirror asthe driver. Any object behind a mirror cannot be shown by this mirror.Additionally, mirrors which are merely made of flat glass show thedriver a small area, except for the mirrors are very close to thedriver. In case they are formed convexly, they generate an imagedistortion. Large vehicles commonly have six or more mirrors which aremounted around the outer side of the vehicle, most of them being convexand distorted which makes it difficult for the driver to pay attentionto all relevant mirrors at the same time. Nevertheless, despite all themirrors, there are still blind spots in the regions of view, i.e. theregions in which no fields of view are located, around these vehicles.

In recent times, it has been increasingly common to consider the use ofcamera systems as device for indirect view either in addition or asreplacement for the mirrors as device for indirect view. In such camerasystems, an image is continuously captured, detected and processed,respectively, and, if so, stored. The (video) data which are captured byan image capture unit with an image sensor device are transmitted, e.g.,by use of a supply unit and, optionally, after processing, to areproduction device which is located in the driver's cabin. Thereproduction device reproduces a view of the respective legallyprescribed field of view or a plurality of fields of view and,optionally, further information such as potential collision risks,distances to other objects, etc. for the area around the vehicle in amanner that the fields of view are permanently visible for the driver atall times. At the same time, view systems promote an improved nightview, more flexible possibilities for arrangement and the possibility toview larger fields of view with a lower distortion.

Permanently visible means in this context that the view into the fieldof view is depicted in a timely uninterrupted manner, that is, notinterrupted by alternatingly showing and hiding the field of view orparts thereof or by overlaying other representations such that the fieldof view cannot be seen completely. Accordingly, the respective field ofview or the fields of view are continuously and in real time shown andmade visible, respectively, on the display device. This holds at leastfor fields of view which are prescribed as permanently visible for allvehicle conditions in which the ignition is switched on and/or,preferably, for example, coupled to a sensor which receives acorresponding signal, for example, a door opening signal or an ignitionswitch signal.

For such mirror replacement systems, partly, cameras with very specificarrangements of objectives and lens systems, respectively, which arecomposed of a plurality of separate lenses are applied, in order to dealwith the specific requirements with regard to the depictioncharacteristics of the camera, the distortion by the opening of theobjective and so on. Thereby, such arrangements of objectives are oftenonly used in a partial portion of the opening of the objective which ispossible at maximum, i.e., a partial image is cut out from the entireimage captured by means of the objective and is used for depictionbecause the arrangement of objectives mainly has the requiredcharacteristics in the used portion and does not have thesecharacteristics in other portions, e.g., border portions.

Commonly, the camera systems are mounted on an outer side of thevehicle, in order to capture a portion around the vehicle. However, bymounting on an outer side of the vehicle, the camera systems aresubjected to environmental impacts, such as pollutions or precipitation.In particular, water drops, for example, rain drops or precipitation byfog or snow, may deposit on the optical element of the camera, such asthe lens of the camera, or generally an element, which closes the camerato the outer side and thereby impair the image data captured by thecamera of the vehicle environment. In particular, it may arise by waterdrops on the camera lens that objects or persons in the vehicleenvironment are hidden partially or completely by the foreign particleand, thus, are not or not satisfactorily shown to the driver on areproduction unit which is usually mounted on the driver's cabin. This,in turn, results in that the driver does not sufficiently or not at allrecognize objects or persons. Thereby, it may arrive at collisions withthe objects or persons not recognized by the driver and, thus,potentially at heavy accidents.

From the prior art, thus, camera systems are known which remove waterdrops by means of an air jet, a wiping apparatus, such as a wiping arm,or by means of a rotating lens or a hydrophobic coating of the lens.Finally, it is also known to position a cylinder around the lens, inorder to hinder water drops to flow onto the lens.

However, the camera systems of the prior art have the drawback that withchanging environmental conditions, such as the change of the winddirection or the quantity of precipitation, the water drops on the lensmay only be removed insufficiently and, thereby, a realistic depictionof the vehicle environment which is well to realize for the driver ofthe vehicle is not possible.

SUMMARY OF THE INVENTION

Accordingly, it is an object of the present invention to provide acamera system for a vehicle, in particular a commercial vehicle, whichallows a reliable removal of water drops from the optical element duringall environmental conditions and also during quick changes betweendifferent environmental conditions.

The disclosure is based on the idea to focus for the removal of waterdrops only on the part of the optical element, which is relevant for adepiction of the vehicle environment, i.e., the use portion of theoptical element. With depiction of a vehicle environment, usually, apart of the vehicle environment is captured by an image capture unit andis correspondingly shown which is significantly larger than the part ofthe vehicle environment which is actually interesting for the driver.For example, it may be the case that due to a certain lens arrangementor lens geometry only a comparatively small part of the captured vehicleenvironment is used for depiction of the same on a reproduction unit.The remaining part of the vehicle environment is not shown to the driveron the reproduction unit. Accordingly, it is irrelevant for a reliableand realistic depiction of the vehicle environment, whether there areone or more water drops on the part of the optical element whichcaptures the portion of the vehicle environment which is not to bedepicted or not, or whether light beams for depiction can even fall onthis part of the optical element or not. In other words, water drops onthe part of the optical element which captures the portion of thevehicle environment which is not to be depicted are anyway not depictedon the reproduction unit why they may stay there, and it is irrelevant,respectively, whether the vehicle environment is captured with this partof the optical element or not. A removal of water drops on the part ofthe optical element, which captures the portion of the vehicleenvironment which is to be shown and, thus, forms the use portion of theoptical element, is requested only there, however, with a largereliability.

Generally, the optical element is the element of the image capture unitwhich is located in an optical path, i.e., the way which is covered bythe light when passing through the image capture unit from a lightsource or the vehicle environment, between the position where the lightenters the image capture unit and the position where the light impactson the image sensor. In other words, the optical element is an elementof the image capture unit which extends until the outermost position ofthe image capture unit and, thus, forms the element of the image captureunit which is directed to the environment of the vehicle. The opticalelement correspondingly has a light incidence portion where the lightbeams from the vehicle environment impact and into which they areguided. The light incidence portion, thus, is the portion of the opticalelements through which the light beams pass and through which they areconsequently optically guided. The use portion of the optical element ispart of the light incidence portion of the optical element. The opticalelement, for example, may be an objective. The optical element isusually supported by a retainer in the camera system. The retainer maybe a sleeve, which encompasses the optical element from the outer sideor a bracket, which grasps the optical element from the outer side, suchas an objective ring. Further constructions for the retainer areconceivable dependent on the geometry and the structure of the opticalelement.

In order to protect the part of the optical element, which is relevantfor depiction of the vehicle environment, from a deposit of water drops,the camera system according to the invention has a protection elementwith a sight opening. The protection element is a component which isseparate to the optical element and which is arranged on the lightincidence portion in the state mounted in the camera system such thatthe provided sight opening leaves the part of the optical element whichis relevant for depiction of the vehicle environment blank, e.g., theprotection element is a lid-similar component. The sight opening is anopening and a concavity, respectively, in the protection element, whichprovides a communication from the outer side of the protection elementto an inner side of the protection element. Conveniently, the sightopening has a geometric shape, which reduces the light beams fallinginto the light incidence portion of the optical element in the mountedstate to a degree, which is required for depiction of the vehicleenvironment on the reproduction unit. Portions of the optical element,which are not relevant for the depiction are hidden such that no lightbeams enter through these hidden portions into the optical element.Thereby, the geometric shape of the sight view is preferably adapted tothe use portion of the optical element. In the mounted state of theprotection element, the sight opening is arranged such that the useportion of the optical element is exposed to the vehicle environment.Thus, the light beams may fall into and enter, respectively, the useportion of the optical element via the sight opening. At the same time,the quantity of water potentially impacting on the optical element isreduced in that a part is completely covered and the use portion isprotected by the protection element at least sidewards.

The protection element is arranged on the optical element such that atleast one gap is present between the optical element and the protectionelement. The gap extends from the edge of the use portion until a waterdrainage opening. The water drainage opening is arranged distally to theuse portion and is open toward the vehicle environment. Distal to theuse portion presently means that the water drainage opening has asignificant distance to the use portion, is preferably arranged at theend of the gap. It does not open toward the use portion.

The water drainage opening may be a bore or notch provided in theprotection element, which constitutes a communication between an innerside and an outer side of the protection element. Alternatively, thewater drainage opening may also be formed in that the protection elementdoes not reach at least partly the retainer at its end distal from thesight opening and, thus, provides a clearance between the retainer andthe protection element through which water may flow to a vehicleenvironment. Thus, the water drainage opening constitutes acommunication between the gap and the vehicle environment. Thereby,water drops which are located on the use portion of the optical elementmay flow into the gap and may exit toward the vehicle environmentthrough the water drainage opening. Because the use portion is acomparatively small portion of the entire light incidence portion, thewater drops often lie at the edge of the use portion or in directproximity thereof and, thus, close to the gap and can thereby easilyflow there into. Water drops, which do not lie in the proximity of thegap, i.e., rather lie in the center of the use portion, may be urgedtoward the edge of the use portion by a convex curvature of the opticalelement, vibrations during driving operation, airflow or combinationsthereof and subsequently may flow into the gap. Once the water drop hasentered the gap, it flows toward the water drainage opening where it isdischarged from the protection element. Because the water drainageopening is arranged distally to the use portion, it is avoided that thewater drop which is discharged through the gap arrives again on the useportion and, due to its remaining there, hinders or impairs the viewinto the vehicle environment.

The protection element may have a lighting device for lighting and,thus, an improved capturing of the vehicle environment. The lightingdevice may, for example, be an infrared light.

Further, the protection element may have a defined coding for attachmentat the correct position relatively to the optical element. The codingmay be a notch, which runs in the longitudinal direction of the retainerof the optical element into which notch a corresponding projection atthe protection element engages and secures the protection elementradially against rotation. Alternatively, the protection element and theretainer of the optical element may each have a colored identificationmark, which, in the correct posture relatively to each other, shows atechnician or a user of the camera system that the protection element islocated in the suitable position relatively to the optical element. Soit is ensured that the sight opening is located, in the mounted state ofthe protection element and the optical element, exactly above/on the useportion of the light incidence portion of the optical element and thatthe vehicle environment may be reliably captured via the use portion.

The protection element may either be screwed by means of a thread ontothe retainer and the optical element, respectively, or may be clamped tothe retainer and the optical element, respectively. In principle, themode of fixation of the protection element at the camera is de-pendenton the construction of the protection element and is dependent onwhether the protection element is a separate component or part of acamera housing or a camera retainer.

The protection element may be formed in two or multiple parts. Forexample, the protection element may consist of a cover plate which isarrange above/on the light incidence portion of the optical element andmay be composed of a ring which is connected to the cover plate (e.g.,by means of a thread) which ring encompasses the optical element or theretainer circumferentially.

The protection element may be provided with a hydrophilic coating. Ahydrophilic coating means a coating, which draws water, such as anano-coating by mineral particles which improve the entering of waterinto the gap.

Preferably, the gap is dimensioned such that it deploys a capillaryaction with receiving of the water drop. A capillary action generallymeans the behavior of fluids to flow against the gravitational forceinto capillaries with contact with the capillaries, i.e., for instance,sufficiently small tubes, gaps or cavities in solids, e.g., to climb inthe capillaries upwards. These effects are caused itself by the surfacetension of fluids and the interfacial surface tension of fluids with thesolid surface (for example: glass). Presently, thus, the gap isconfigured such that it forms a capillary. With contact of a water dropwith the opening of the gap, the water drop is drawn into the gap by thecapillary action, i.e., a suction effect is generated by the capillaryaction by which the drop is dragged into the gap. For achieving of acapillary action, the gap may, for example, be dimensioned in dependencyon the size of the drop to be removed. For example, it may be that dropssmaller than 0.5 mm are considered as not disturbing for the depictionof the vehicle environment. Then, the gap is configured such that itcauses at least a capillary action for drops equal to or larger than 0.5mm.

According to a preferred embodiment, the optical element has ahydrophobic coating, which has a sufficient light transmission forcapturing of the vehicle environment. A hydrophobic coating means awater-repellent coating, which is provided/applied by a suitable surfacetreatment of the optical element or which is formed by a suitablematerial. A water-repellent coating has the advantage that water dropswhich are not located at the edge of the use portion and, thus, indirect proximity to the gap may easily slide to the edge of the useportion by vehicle vibrations during vehicle operation, airflow orcombinations thereof. Further, the capillary action is intensified by ahydrophobic coating in that a contact angle relatively to the fluid isincreased and the water drop tends to flow into the gap. The contactangle mean the angle between the water drop and the surface of the useportion of the optical element. With a small contact angle, the waterdrop lies relatively flat on the use portion, whereas, with a largecon-tact angle, the water drop rather maintains its drop shape and,thus, a smaller contact surface is present between the water drop andthe use portion. Alternatively, a hydrophobic and, thus, water-repellentsurface may also be achieved by providing a certain roughness or grain.Further, a hydrophobic coating of the optical element protects theoptical element against wear. With provision of a hydrophobic coating,the gap is dimensioned in dependency on the hydrophobic coating and,thus, the predetermined drop shape. Alternatively or additionally, thegap may also be dimensioned based on the curvature of the first opticalelement.

Preferably, the gap has a cross-section, which changes along itsextension. Thereby, in particular the capillary action may be increasedbecause the gap generates a capillary action for water drops ofdifferent diameters and sizes, respectively. For example, the gap may beconfigured narrow at the edge of the sight opening and expanding towardthe water drainage opening. Thereby, it is ensured that drops of allsizes and geometries may flow into the gap and, there-by, a capillaryaction is caused right from the beginning regardless of the size of thedrop. However, it is also conceivable that the cross-section of the gapdecreases along its extension with increasing distance from the sightopening. Thus, a capillary action is generated for relatively largewater drops on the use portion only, smaller water drops flow into thegap without capillary action. However, by the increasing narrowing ofthe gap in moving direction of the water drop, a capillary action isalso achieved for smaller water drops and water drops of any sizereliably flow through the gap to the water drainage opening where theyare discharged to the vehicle environment.

Preferably, the gap is formed by at least one inner notch which isprovided in at least a surface of the protection element which faces thelight incidence portion of the optical element. The inner notch is arecess in the surface of the protection element which corresponds to atleast the surface which faces the light incidence portion of the opticalelement and, thus, corresponds to the inner side of the protectionelement, which is oriented toward the light incidence portion of theoptical element. The inner notch, however, may also extend alongsurfaces of the protection element which lie further inwards. With morethan one inner notch, the inner notches may have different crosssections, which extend laterally to the flowing direction (differentsizes and/or shapes). The inner notch may also extend in a portion ofthe inner surface of the protection element only, such as close to thesight opening.

The inner notch advantageously extends radially to an outer side of thesurface of the protection element, which is oriented toward the lightincidence portion. Alternatively, the inner notch may extend spirally toan outer side of the light incidence portion. The spiral extension ofthe inner notch, thereby, runs around the view opening. Furtheralternatively, the inner notch may extend approximately concentricallyaround the sight opening of the protection element.

Alternatively or additionally, the inner notch may have a cross sectionin the direction to an outer side of the surface of the protectionelement, which is oriented toward the light incidence portion, whichcross-section changes laterally to the flowing direction of the drop.For example, the inner notch may be configured such that it expands froman inner side of the protection element toward an outer side of theprotection element. Alternatively, the inner notch may have anarc-shaped, triangular, etc. cross section. Also a cross section, whichchanges in the outward direction of the light incidence portion lateralto the flowing direction of the drop has the advantage that thecapillary action is further improved and the inner notch can be used fora plurality of drop sizes.

According to a preferred embodiment, the inner notch forms a channelfrom the sight opening to the water drainage opening. In other words,the inner notch extends from the edge of the sight opening to the waterdrainage opening.

Alternatively to the embodiments, in which an inner notch is used fordischarging the water drop, a gap may also be formed in that the surfaceof the protection element facing the optical element is spaced from thelight incidence portion of the optical element. That is, the protectionelement is entirely and, thus, not only partially arranged in a certaindistance to the light incidence portion and the gap radially extendsalong the entire protection element.

In order to ensure a defined distance of the protection element from theoptical element, the surface of the protection element facing theoptical element has at least one rib, which sup-ports the protectionelement at the retainer and/or the optical element. With two ribs, aninner notch may be formed. In case of multiple ribs, a plurality ofinner notches may be formed.

Preferably, an outer side of the protection element has a geometry(e.g., at least one outer notch), which generates an air swirl. The airswirl may promote a movement of a water drop which is located on the useportion toward the gap and/or may prevent a movement of a water droplocated on an outer side of the protection element toward the sightopening. For example, the geometry on the outer side is configured, suchthat the water drop is selectively guided away from the sight opening,such as by at least one outer notch, rib or seam, which are arrangedconcentrically around the sight opening or are radially extending awayfrom the sight opening on the outer side of the protection element.

Alternatively or additionally, the protection element may have a nozzle,which applies a medium onto the light incidence portion of the opticalelement and, thus, promotes a movement of a water drop located on theuse portion toward the gap and/or prevents a movement of a water droplocated on an outer side of the protection element toward the sightopening. The nozzle may be an air nozzle, which applies air onto the useportion of the light incidence portion. In this respect, the air nozzlemay be arranged on the outer side of the protection element or insidethe protection element, such as in the gap. Alternatively, the nozzlemay be an air nozzle, which is arranged at an outer side of or close tothe protection element and applies air to either the use portion of thelight incidence portion or to an outer side of the protection element.Further, alternatively or additionally, the air nozzle may be arrangedsuch that it blows at least partially air directly into the gap and,thus, additionally urges the drops into the gap.

The protection element may be a lid, which is provided separately to theoptical element and the retainer of the optical element, but can also bepart of a camera housing or a camera retainer. For example, theprotection element may be part of a camera arm and may be connectedthereto by means of a ridge/bar. The protection element, therefore, isconfigured detachably and exchangeable such that, for example, forcleaning or maintenance and repair, respectively, of the optical elementit may be removed from the optical element.

In order to deice the camera and, in particular, the optical element orto remove condensed water from the optical element, the protectionelement further has a heating element. The heating element is preferablya heating foil, but may also be a heating wire, and is preferablyarranged in the gap. Generally, the heating element may be fixeddirectly to the protection element, for example, by using a heating wireby means of inserting and molding or by using a heating foil by adhesivebonding. However, the gap may not be completely closed by the heatingelement such that water drops may further be reliably discharged throughthe gap. In particular, with provision of a heating element, it may beadvantageous, if the protection element is configured from two ormultiple parts, because this facilitates the installation of the heatingelement.

According to a preferred embodiment, the protection element is made of apolymer, such as a thermoplastic, a thermosetting plastic, an elastomeror combinations thereof. Alternatively, the protection element may alsobe made of a metallic material. Furthermore, the protection element ispreferably manufactured from an opaque material, but may also bemanufactured from a transparent material. An opaque material has theadvantage that no light beams may fall from the vehicle environment intothe part of the light incidence portion of the optical element, whichdoes not correspond to the use portion. Thus, no optical interferences,such as reflections or the like, may disturb the depiction of thevehicle environment on the image sensor.

According to a preferred embodiment, the protection element has aShore-hardness of less than 60 Shore and, thus, fulfils legalprescriptions (e.g., UN ECE/R46) for materials for components, whichhave sharp edges (such as ribs at the protection element).

Preferably, the sight opening and the gap are dimensioned, such that anadjustment of the camera in a certain range is possible without hidingthe use portion by the protection element and closing the gap. In thisrespect, the sight opening may be larger than the use portion, and thegap may be dimensioned such that it is not closed by approaching of theretainer or the optical element to the protection element, despite arotation of the camera in a certain range, such as around 10 degree.This is in particular advantageous, if the protection element is part ofthe camera housing and an adjustment of the camera does not result in anadjustment of the protection element, too, however, may also beadvantageous for other constructions, wherein the protection element isattached directly on the optical element and/or the retainer.

Preferably, the camera system is part of a mirror replacement system,e.g., as it is defined in the UN regulation UN ECE/R46.

Because the camera system according to the invention focusses only to acertain part of the light incidence portion, namely the use portion, ofthe optical element with respect to protection and removal of waterdrops, the camera system according to the invention has the ad-vantagein view of the camera systems known from the prior art that, on the oneside, it is pre-vented that, in principle, water drops land on therelatively small use portion of the optical element of a camera, on theother side, however, water drops, which deposit here nevertheless, arequickly removed. By the quick removal of the water drops, alsorelatively large quantities of water, such as during a heavy rainfall,may be managed. The protection element, further, protects the coveredpart of the light incidence portion against mechanical influences, suchas stone chipping or scratches by branches, against optical effects,i.e., unwanted light effects, against freezing and against UV-radiation.The protection element, furthermore, promotes the integration of furtherauxiliary components, such as the nozzle, the lighting and the heatingelement, in an easy manner. Finally, the protection element makes itpossible to prevent light beams, which are irrelevant or eveninappropriate for the vehicle environment to be depicted to impact onthe use portion by the selective arrangement of the sight opening on theuse portion of the optical element. Thus, inter alia, negative effectsto the image depiction, such as light refractions or reflections, may beprevented.

Other objects and features of the present invention will become apparentfrom the following detailed description considered in conjunction withthe accompanying drawings. It is to be understood, however, that thedrawings are designed solely for purposes of illustration and not as adefinition of the limits of the invention, for which reference should bemade to the appended claims. It should be further understood that thedrawings are not necessarily drawn to scale and that, unless otherwiseindicated, they are merely intended to conceptually illustrate thestructures and procedures described herein.

BRIEF DESCRIPTION OF THE DRAWINGS

In the following, the invention is exemplarily described by reference tothe accompanying figures, in which:

FIG. 1 a plan view of a vehicle with a left and right camera system,

FIG. 2 shows a schematic representation of a view system with a camerasystem known from the prior art,

FIG. 3 shows a schematic representation of a view system with a camerasystem according to the invention of a first embodiment in a firststate,

FIG. 4 shows a schematic representation of the view system of FIG. 3 ina second state,

FIG. 5 shows a front view of the camera system according to theinvention of FIG. 4,

FIG. 6 shows a schematic representation of a camera system of a secondembodiment,

FIG. 7 shows a schematic representation of a camera system of a thirdembodiment,

FIG. 8 shows a schematic representation of a camera system of a fourthembodiment,

FIG. 9 shows a schematic representation of a camera system of a fifthembodiment,

FIG. 10 shows a perspective representation of a camera system of a sixthembodiment in a mounted state,

FIG. 11 shows a perspective representation of the camera system of FIG.10 in a demounted state,

FIG. 12 shows a schematic representation of the camera system of FIG. 10with a heating element,

FIG. 13 shows a perspective representation of the camera system of FIG.12,

FIG. 14 shows a schematic representation of the camera system of FIG. 8with heating element,

FIG. 15 shows a schematic representation of a camera system of FIG. 8with air nozzle,

FIG. 16 shows a perspective representation of the camera system of FIG.3 in a demounted state,

FIG. 17 shows a perspective representation of the camera system of FIG.16 in a mounted state,

FIG. 18 shows a schematic representation of a further camera system,

FIG. 19 shows a plan view on and a section through the protectionelement according to the invention of the first embodiment, and

FIG. 20 shows different views of a protection element according to theinvention.

DETAILED DESCRIPTION OF THE PRESENTLY PREFERRED EMBODIMENTS

FIG. 1 shows a plan view of a commercial vehicle F presently a truckwith a tractor and a semi-trailer/trailer. A camera system 100 isattached to each of the left and right sides of the tractor. The camerasystem 100 captures an environment around the vehicle F by means of ause portion NB of an optical element 11.

FIG. 2 schematically shows a view system known from the prior art. Theview system has a processing unit 20, such as an ECU, and a reproductionunit 30, such as a monitor, e.g., a TFT-, LCD-monitor. A depictedportion 31 is present on the reproduction unit 30.

The view system further has a camera system 100, which comprises acamera 10, such as a camera with a CMOS- or CCD-technology. The camera10 has an optical element 11, such as an objective, and a retainer 13.The retainer 13 circumferentially supports the optical element 11. Theoptical element 11 has a light incidence portion EB at a surface 12directed to the vehicle environment, which light incidence portion EB isconfigured convexly. The light incidence portion EB is the portion ofthe optical element 11 into which light beams of a vehicle environmententer into the optical element 11. A part of the light beams which enterinto the light incidence portion EB is depicted on an image sensor (notshown) and, thus, projects the vehicle environment on the image sensor.The part of the light incidence portion EB onto which the light beamsimpact, which are depicted on the image sensor and which are depicted onthe portion of the image sensor, respectively, which is represented tothe driver, is called use portion NB of the optical element 11.

FIG. 3 schematically shows a view system with a camera system 100according to the invention. As the view system shown in FIG. 2, the viewsystem shown in FIG. 3 also has a processing unit 20 and a reproductionunit 30. The camera system 100 of FIG. 3 differs from the camera systemof FIG. 2 in that it is additionally provided with a protection element40. The protection element 40 is configured as a kind of lid, which isarranged on the optical element 11 and is fixed to the optical element11 and the retainer (not shown in FIG. 3), respectively, via a clampingjoint. The protection element 40 is an additional component, which isseparate to the retainer 13 of the optical element 11. In particular,preferably, the protection element 40 is removable from the camerasystem 100, without destroying the optical element 11 and itsarrangement in its retainer. In other words, the optical element 11, theretainer 13 and the image sensor form a permanent/inseparable unit,which has to cooperate together for the function of the camera 10,whereas the protection element 40 is an additional component, which maybe provided on the camera 10, in order to protect the use portion NB ofthe optical element 11 against water deposition or in order toselectively remove possible water depositions on the use portion NB ofthe optical element 11. Therefore, the protection element 40 may also beretro-fitted with existing cameras 10.

The protection element 40 has at the side, which covers the lightincidence portion EB of the optical element 11 a sight opening 41. Thesight opening 41 is a through-opening, which connects an outer side ofthe protection element 40 with an inner side of the protection element40. That is, the sight opening 41 is a recessed, open portion of theprotection element 40. The size and geometry of the sight opening 41corresponds approximately to the size and geometry of the use portionNB. At the end of the protection element 40, which is located distal tothe sight opening 41, a water drainage opening 43 in shape of a bore isprovided in the protection element 40. The water drainage opening 43constitutes a communication between an inner side of the protectionelement 40 and an outer side of the protection element 40. Theprotection element 40 is spaced from the optical element 11 such that agap 42 is present between the optical element 11 and the protectionelement 40.

As shown in FIG. 3, a water drop T is located on the surface 12 of theoptical element 11, which faces a vehicle environment. Specifically, thewater drop T is arranged on the convex light incidence portion EB of theoptical element 11 such that it lies partially on the use portion NB ofthe optical element 11 (first state). This results in that the lightbeams, which fall into the optical element 11 through the use portion NBdepict the water drop T on the image sensor and, thus, the depictedportion 31 of the reproduction unit 30, namely, as dark spot 32.

In FIG. 4, the camera system 100 of FIG. 3 is shown. Contrary to thefirst state shown in FIG. 3, in FIG. 4, the water drop T is flowed intothe gap (second state) and is no longer depicted on the image sensorand, thus, the depicted portion 31 of the reproduction unit 30. Forexample, the water drop T may arrive in the gap 42 in that it is movedby the airflow and/or vibrations during driving operation of the vehicleF to an outer side of the use portion NB. In case of a contact betweenthe water drop T and the entrance into the gap 42 at the sight opening41, the water drop T slides into the gap 42. There, it moves by airflowand/or vibrations and/or subsequent water drops T within the protectionelement 40 away from the sight opening 41 toward the water drainageopening 43 and is discharged through the water drainage opening 43 fromthe gap 42 to the vehicle environment. In this way, it can be preventedthat, during strong precipitation, such as heavy rain fall, the gap 42and the clearance between the protection element 40 and the opticalelement 11 and the retainer 13, respectively, is filled with water anddisturbs the function of the optical element 11, in that no furtherwater drops may be discharged or—with corresponding weatherconditions—the water freezes in the gap 42 and the clearance between theprotection element 40 and the optical element 11 and the retainer 13,respectively, and damages the protection element 40.

Alternatively or additionally, with a suitable dimensioning of the gap42, the water drop T may also be drawn into the gap 42 by capillaryaction, as soon as it contacts the entrance of the gap 42. As thecapillary action is dependent on the size of the gap 42 relative to thesize of the water drop T, the gap may have a cross section, whichchanges along its extension or changes laterally to the flowingdirection of the water drop, in order to reliably remove in this way asmany water drops as possible, which differ in shape and size, from theuse portion NB of the optical element. The usage of the capillary actionhas the advantage that the water drops T, which are located on the useportion NB, may flow away faster than compared to no capillary actionand also in directions, which otherwise would not allow a movement ofdrops due to the gravity.

In FIG. 5, a front view of the camera system of FIG. 4 is shown. Asshown in FIG. 5, the geometry and size of the sight opening 41 of theprotection element 40 corresponds approximately to the geometry and sizeof the use portion NB. Specifically, the sight opening 41 is slightlylarger than the use portion NB and is a regular rectangle. However, itshould be understood that the use portion NB and, thus, also the sightopening 41 may adopt each other geometry and size—dependent on theoptical element 11 and the requirements on the use portion NB.

FIG. 6 to FIG. 9 show different embodiments (a second to fifthembodiment) of the protection element 40 according to the invention.

In FIG. 6, a second embodiment of the protection element 40A is shown.In contrast to the first embodiment of the protection element 40, theprotection element 40A has, on the outer side, which is opposed to thelight incidence portion EB, a circumferential outer notch 15. The outernotch 15 is provided concentrically around a sight opening 41A andserves for swirling of air, in order to urge water drops, which arelocated on the use portion NB, toward a gap 42E and/or to hinder waterdrops T, which are located on the outer side of the protection element40A to flow onto the use portion NB. As the protection element 40,protection element 40A also has a water drainage opening distal from thesight opening 41A.

In FIG. 7, a third embodiment of the protection element 40B is shown. Inthe embodiment of protection element 40B shown in FIG. 7, the protectionelement 40B is part of a camera housing (not shown). In this case, thewater drops T do not directly flow to the vehicle environment via thewater drainage opening 43B, but firstly flow into the camera housing.However, in order to selectively discharge the water drops T to thevehicle environment, presently, also the camera housing has to have anopening, which constitutes a communication to the vehicle environmentand ensures a discharge of the water drops. The protection element 40Bshown in FIG. 7 has a sight opening 41B and a gap 42B, as they havealready been described above with respect to the protection elements 40and 40A.

In FIG. 8, a fourth embodiment of the protection element 40C is shown,which differs from the second embodiment shown in FIG. 6 in that thewater drainage opening 43C is formed by providing a notch in the innersurface of the protection element 40C. Further, the protection element40C is not clamped with the optical element 11 and the retainer 13,respectively, as shown in FIG. 3, but is connected to the opticalelement 11 and the retainer 13, respectively, by means of a threadedconnection 46. The protection element 40C shown in FIG. 8 has a sightopening 41C and a gap 42C as they have already been described above withrespect to the protection elements 40, 40A and 40B.

In FIG. 9, a fifth embodiment of the protection element 40D is shown. Incontrast to the previous embodiments of the protection element 40, 40A,40B, 40C, the protection element 40D is part of a camera retainer and acamera housing, specifically a camera arm (not shown). In this respect,the protection element is connected with the camera arm via ridges/bars(not shown). As with the embodiment shown in FIG. 7, with the protectionelement 40D, the water drops are also not directly discharged to thevehicle environment after passing of the gap 42D and the water drainageopening 43D, but are firstly discharged into the camera arm and, fromthere, are discharged to the vehicle environment via a correspondingopening in the camera arm. The protection element 40B shown in FIG. 9has a sight opening 41D as it has already been described above withrespect to the protection elements 40, 40A, 40B, 40C.

In particular, with respect to the embodiments shown in FIGS. 7 and 9,in which the protection element 40B, 40D is formed as part of a camerahousing, it may be advantageous, if the sight openings 41B and 41D areconfigured slightly larger than the use portion NB. This has theadvantage that the camera 100 may be rotated and adjusted, respectively,in a certain frame, which is predetermined by the size and the geometryof the sight opening 41B, 41D, without closing the gap 42B, 42D with thecamera 100 (in particular with the optical element 11 or the retainer13) or covering the use portion NB with the protection element 40B, 40D.

In FIG. 10, a sixth embodiment of the protection element 40E is shown ina mounted state. The protection element 40E shown in FIG. 10 mainlydiffers from the previous protection elements 40, 40A, 40B, 40C and 40Din that it is provided with a plurality of (in FIG. 10: three)concentrically arranged outer notches 15 on its outer surface and withspring shackles 47 along is circumference. As already described withrespect to the embodiment in FIG. 6, the outer notches 15 serve forswirling of air in order to urge water drops T, which are located on theuse portion NB, toward a gap 42E and/or in order to hinder water dropsT, which are located on the outer side of the protection element 40E toflow onto the use portion NB. As it is shown in FIG. 10, the sightopening 41E is configured approximately rectangular and is arrangedoff-center and eccentrically, respectively, with respect to theprotection element 40E.

The spring shackles (rips) 47 are small metal plates, which projectapproximately vertically to the sight opening 41 E from a distal edge ofthe protection element 40E along the circumference of the protectionelement 40E. Due to their elastic configuration, they allow a simple,but also reliable attachment of the protection element 40E at an opticalelement 11.

FIG. 11 shows the embodiment of protection element 40E shown in FIG. 10in a demounted state. As shown in FIG. 11, an objective ring 14 isattached around the optical element 11 which objective ring 14 has asurface, which is inclined upwards to a center of the optical elementsuch that a valley is present between the light incidence portion EB ofthe optical element 11 and the objective ring 14. This valley isdisadvantageous without providing a protection element 40E and a gap42E, because water drops T may entangle there. However, by providing theprotection element 40E and the gap 42E, water drops T may also in thiscase be reliably transported away via the gap 42E and the water drainageopening 43E.

FIGS. 12 and 13 show the protection element 40E of FIG. 11. In the gap42E, a heating element 17 is introduced between the protection element40E and the optical element 11. The heating element 17 is a ring-shapedelement as shown in FIG. 13, which is energized with electricity via twocables and, thus, is heated. For example, the heating element 17 is aheating wire. Alternatively, the heating element 17 may also be aheating foil, which is preferably bonded on an inner side of theprotection element 40E, which forms the gap 42E. The heating element 17serves for deicing the camera and, in particular, the optical element orfor removing condensed water from the optical element by evaporation.

FIG. 14 shows the protection element 40C of FIG. 8 with a heatingelement in the gap 42C.

FIG. 15 shows the embodiment of protection element 40C of FIG. 8 with anair nozzle 19, which is attached to an outer surface of the protectionelement 40. The air nozzle 19 is configured for blowing air onto the useportion NB and, thus, for selectively urging the water drops T, whichare potentially located there during operation, toward an edge portionof the use portion NB, i.e., toward the protection element 40C and thegap 42C. Alternatively, the air nozzle may also be arranged such that ithinders water drops T on an outer side of the protection element 40C toreach the use portion NB. There may also be provided more than one airnozzle and/or the air nozzle may be combined with a heating element 17.

FIGS. 16 and 17 show a camera system according to the invention with aprotection element 40F, which is configured as a lid, which is arrangedin a certain distance on the optical element. The protection element 40Fhas outer notches, which run radially on the outer side, which liesopposite to the light incidence portion, which outer notches hinderwater drops T on the outer side of the protection element 40F to reachonto the use portion NB. Rather, the water drops T on the outer side ofthe protection element 40F are urged into the outer notches byvibrations of the vehicle during driving operation and/or by air flowand, there, are radially guided to an outer circumference of theprotection element. With the embodiment shown in FIGS. 16 and 17, theouter notches 15 are formed by ridges and ribs, which are applied onto aring, which ridges and ribs, respectively, project in a directionradially inwards and, thus, form channels between the ribs into whichalso water drops T on the use portion NB may enter. It is alsoconceivable to provide the embodiment shown in FIGS. 16 and 17 without agap between the protection element 40F and the optical element 11 suchthat water drops T on the use portion NB may be exclusively dischargedvia the outer notches 15.

FIG. 18 shows a camera system wherein the protection element 40G isintegrated into the retainer 13G of the optical element 11, i.e., ispreferably formed as a single component. In particular, in this case, agap for discharging of water drops T, which are located on the surfaceof the optical element 11, may be configured to such that it usescapillary action.

FIG. 19 shows a detailed plan view of and a cross section through theprotection element 40 of the first embodiment. As it is shown in FIG.19, the outer notches 15 are formed on the protection element 40 as tocircles, which are concentrically arranged around the center of theprotection element 40, and the gap 42 between the optical element 11 andthe protection element 40 decreases/narrows from a portion, which isadjacent to the sight opening 41, toward an outer circumference of thelight incidence portion.

FIG. 20 shows different views of the protection element 40. Inparticular, FIG. 20 shows a perspective lower view as well as a viewdirectly from below of the protection element 40, which show that thegap 42 is formed by a plurality of inner notches 49, which run radiallyto an outer circumference of the protection element 40 and, thus, formchannels for discharging of water drops T. With the embodiment shown inFIG. 20, the inner notches are formed by attaching ribs 47 on an innersurface of the protection element 40. Finally, it can further be takenfrom FIG. 20 that the water drainage opening 43 may be arranged at anedge of the protection element 40 as a groove.

In principle, it is also conceivable to provide the camera systemwithout water drainage opening, as long as it is ensured that the waterentering into the gap is that little that it is removed by evaporationbefore it accumulates in a noteworthy quantity in the gap.

It is explicitly stated that all features disclosed in the descriptionand/or the claims are intended to be disclosed separately andindependently from each other for the purpose of original disclosure aswell as for the purpose of restricting the claimed invention independentof the composition of the features in the embodiments and/or the claims.It is explicitly stated that all value ranges or indications of groupsof entities disclose every possible intermediate value or intermediateentity for the purpose of original disclosure as well as for the purposeof restricting the claimed invention, in particular as limits of valueranges.

Thus, while there have shown and described and pointed out fundamentalnovel features of the invention as applied to a preferred embodimentthereof, it will be understood that various omissions and substitutionsand changes in the form and details of the devices illustrated, and intheir operation, may be made by those skilled in the art withoutdeparting from the spirit of the invention. For example, it is expresslyintended that all combinations of those elements and/or method stepswhich perform substantially the same function in substantially the sameway to achieve the same results are within the scope of the invention.Moreover, it should be recognized that structures and/or elements and/ormethod steps shown and/or described in connection with any disclosedform or embodiment of the invention may be incorporated in any otherdisclosed or described or suggested form or embodiment as a generalmatter of design choice. It is the intention, therefore, to be limitedonly as indicated by the scope of the claims appended hereto.

What is claimed is:
 1. A camera system for a vehicle (F), comprising acamera for capturing a vehicle environment, wherein the camera has anoptical element, which has a light incidence portion (EB), and aretainer, which supports the optical element, and a protection element,which is positioned separately to the optical element and the retainerat least via the light incidence portion (EB) of the optical element andhas a sight opening, which exposes a use portion (NB) of the lightincidence portion (EB), wherein at least one gap is present between theoptical element and the protection element for capturing a water drop(T), which is located on the use portion (NB), and wherein a waterdrainage opening is provided distally from the sight opening.
 2. Thecamera system according to claim 1, wherein the gap is dimensioned suchthat it develops a capillary action with receiving the water drop (T).3. The camera system according to claim 1, wherein the optical elementhas a hydrophobic coating.
 4. The camera system according to claim 1,wherein the gap has a cross section, which changes along its extension.5. The camera system according to claim 1, wherein the gap is formed byan inner notch, which is provided in at least one surface of theprotection element, which surface faces the light incidence portion (EB)of the optical element.
 6. The camera system according to claim 5,wherein the inner notch radially extends toward an outer side of thelight incidence portion (EB).
 7. The camera system according to claim 5,wherein the inner notch spirally extends toward an outer side of thelight incidence portion (EB).
 8. The camera system according to claim 5,wherein the inner notch extends approximately concentrically around thesight opening of the protection element.
 9. The camera system accordingto claim 5, wherein the inner notch has a cross section, which changestoward an outer direction of the light incidence portion (EB) laterallyto the flowing direction of the water drop (T).
 10. The camera systemaccording to claim 5, wherein the inner notch forms a channel from thesight opening to the water drainage opening.
 11. The camera systemaccording to claim 1, wherein the gap is formed in that the surface ofthe protection element facing the optical element is spaced from thelight incidence portion (EB) of the optical element.
 12. The camerasystem according to claim 1, wherein the surface of the protectionelement facing the optical element has at least one rib for providing adefined distance of the protection element from the optical element. 13.The camera system according to claim 1, wherein an outer side of theprotection element has a geometry, which causes an air swirl forpromoting a movement of a water drop (T), which is located on the useportion (NB) toward the gap and/or for preventing a movement of a waterdrop (T), which is located on an outer side of the protection element,toward the sight opening.
 14. The camera system according to claim 1,wherein the protection element has a nozzle, which applies a medium ontothe light incidence portion (EB) of the optical element for promoting amovement of a water drop (T), which is located on the use portion,toward the gap and/or for preventing a movement of a water drop (T),which is located on the outer side of the protection element, toward thesight opening.
 15. The camera system according to claim 1, wherein theprotection element is a part of the camera housing or a camera retainer.16. The camera system according to claim 1, wherein the protectionelement further has a heating element.
 17. The camera system accordingto claim 16, wherein the heating element is arranged in the gap.
 18. Thecamera system according to claim 16, wherein the heating element is aheating film.
 19. The camera system according to claim 1, wherein theprotection element is formed of a thermoplastic, a thermosettingplastic, an elastomer, a metallic material or combinations thereof. 20.The camera system according to claim 19, wherein the protection elementhas a Shore-hardness of less than 60 Shore.
 21. The camera systemaccording to claim 1, wherein the sight opening and the gap aredimensioned such that an adjustment of the camera in a certain range ispossible without covering the use portion (NB) by the protection elementand closing the gap.
 22. The camera system according to claim 1, whereinthe protection element has a hydrophilic coating.
 23. The camera systemaccording to claim 1, wherein the camera system is part of a mirrorreplacement system.